text: # Copyright 2017 Google LLC
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  """Helpers for deprecated code and modules."""
  
  import warnings
  
  import pkg_resources
  
  
  def complain(distribution_name):
      """Issue a warning if `distribution_name` is installed.
  
      In a future release, this method will be updated to raise ImportError
      rather than just send a warning.
  
      Args:
          distribution_name (str): The name of the obsolete distribution.
      """
      try:
          pkg_resources.get_distribution(distribution_name)
          warnings.warn(
              "The {pkg} distribution is now obsolete. "
              "Please `pip uninstall {pkg}`. "
              "In the future, this warning will become an ImportError.".format(
                  pkg=distribution_name
              ),
              DeprecationWarning,
          )
      except pkg_resources.DistributionNotFound:
          pass
  